TOKYO — South Korea’s president tried late Sunday to dismiss talk of a dispute between Seoul and Washington over how to deal with North Korea following its sixth nuclear test, after President Trump criticized the South Korean approach as “appeasement.”

Moon Jae-in’s office said that his government would continue to work towards peaceful denuclearization after tweets and actions from Trump that have left South Koreans scratching their heads at why the American president is attacking an ally at such a sensitive time.

As if to underline Seoul’s willingness to be tough, the South Korean military conducted bombing drills at dawn Monday, practicing ballistic missile strikes on the North Korean nuclear test site at Punggye-ri.

The South Korean military calculated the distance to the site and practiced having F-15 jet fighters accurately hit the target, the joint chiefs of staff said Monday morning.

“This drill was conducted to send a strong warning to North Korea for its sixth nuclear test,” it said.

After North Korea conducted its nuclear test Sunday, Trump tweeted: “South Korea is finding, as I have told them, that their talk of appeasement with North Korea will not work, they only understand one thing!”

Trump did not talk to Moon on the phone Sunday — in stark contrast to the two calls he had with Shinzo Abe, the prime minister of Japan and a leader who has proven much more willing to agree with his American counterpart. This will worsen anxieties in Seoul that Tokyo is seen as “the favorite ally,” analysts said.

Moon, who was elected in May, advocated engagement with North Korea but has also acknowledged the need for pressure to bring the Pyongyang regime back to talks. He has also come around to an agreement between his predecessor and the U.S. military to deploy an antimissile system in South Korea.

Trump’s tweet was widely reported across South Korean media, and Moon’s office responded to the tweet with a measured statement Sunday night.

“South Korea is a country that experienced a fratricidal war. The destruction of war should not be repeated in this land,” it said. “We will not give up and will continue to push for the denuclearization of the Korean Peninsula through peaceful means working together with our allies.”

North Koreans watch a news report showing North Korea's nuclear test on a screen in Pyongyang, North Korea. Kyodo/via REUTERS (Kyodo/Reuters)

Analysts said Trump’s actions were puzzling.

“It’s strange to see Trump going after South Korea more aggressively than he’s going after China, especially since China also thinks that dialogue is central to solving this problem,” said John Delury, a professor of international relations at Yonsei University in Seoul.

In an earlier tweet, Trump had said that China “was trying to help,” although he added it was “with little success.”

Delury said that the “passive aggressive” tone of Trump’s tweets suggested that Moon had been standing up to the American president during their previous phone calls. They spoke Friday after North Korea sent a missile over Japan.

“It sounds like Moon is saying, ‘We’re going to have to talk to these guys’ — which is true — and Trump is frustrated,” Delury said, noting that the latest tweet seemed to address Moon directly, with its “like I told you.”

Trump’s tweet was even more puzzling, analysts say, because Trump himself — both as a candidate and as president — had repeatedly suggested he would be willing to talk to North Korea’s leader, Kim Jong Un.

On the campaign trail, Trump said that he would be happy to have a burger in a boardroom with Kim, and in recent months he has called Kim a “smart cookie” and has said he would be “honored” to meet him.

South Korea’s response overall to Trump’s recent pronouncements has been much more muted than its past explosions against its protector — a sign that they know Trump is a different kind of president.

“They think they’re dealing with an unreasonable partner and complaining about it isn’t going to help — in fact, it might make it worse,” said David Straub, a former State Department official who dealt with both Koreas and recently published a book about anti-Americanism in South Korea.

“Opinion polls show South Koreans have one of the lowest rates of regard for Trump in the world and they don’t consider him to be a reasonable person,” Straub said. “In fact, they worry he’s kind of nuts, but they still want the alliance.”

On the Sunday talk shows in the United States, there was plenty of criticism of Trump’s words.

“You gotta watch the tweets,” Michael Hayden, a retired Air Force general and former head of the National Security Agency and the CIA who has been critical of Trump, said on CNN’s “State of the Union.”

“I think we had an unforced error over the weekend when we brought up the free trade agreement with our South Korea friends on whom we have to cooperate. . . . It’s wrong on the merits, and it’s certainly not integrated into a broader approach to northeast Asia,” Hayden said. He served as NSA director from 1999 to 2005 and led the CIA from 2006 until 2009.

Rep. Adam B. Schiff (D-Calif.), the top Democrat on the House Intelligence Committee, also questioned Trump’s decision to admonish South Korea when the nation appears to be facing a growing threat.

“We need to be working hand in hand with South Korea, and with Japan,” he said, also on CNN. “Why we would want to show divisions with South Korea makes no sense at all.”

Even before the nuclear test, Trump’s approach to South Korea, an ally since the end of World War II, had been under question. Analysts were asking why Trump would rip up the free-trade agreement with South Korea at all, rather than revising it, let alone at a time when a united front was needed in the region.

Treasury Secretary Steven Mnuchin said that “no decisions” had been made but that trade deals must be in the United States’ economic interest.

“The president has made clear that where we have trade deficits with countries, we’re going to renegotiate those deals,” Mnuchin said on Fox News.

Yoonjung Seo in Seoul and Hamza Shaban in Washington contributed to this report.